1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <stdio.h> 18 #include <stdlib.h> 19 20 #include <fstream> 21 #include <functional> 22 #include <iostream> 23 #include <string> 24 #include <vector> 25 #include <set> 26 #include <map> 27 #include <unordered_set> 28 29 #include "art_method-inl.h" 30 #include "base/unix_file/fd_file.h" 31 #include "base/stringprintf.h" 32 #include "gc/space/image_space.h" 33 #include "gc/heap.h" 34 #include "mirror/class-inl.h" 35 #include "mirror/object-inl.h" 36 #include "image.h" 37 #include "scoped_thread_state_change.h" 38 #include "os.h" 39 40 #include "cmdline.h" 41 #include "backtrace/BacktraceMap.h" 42 43 #include <sys/stat.h> 44 #include <sys/types.h> 45 #include <signal.h> 46 47 namespace art { 48 49 class ImgDiagDumper { 50 public: 51 explicit ImgDiagDumper(std::ostream* os, 52 const ImageHeader& image_header, 53 const std::string& image_location, 54 pid_t image_diff_pid, 55 pid_t zygote_diff_pid) 56 : os_(os), 57 image_header_(image_header), 58 image_location_(image_location), 59 image_diff_pid_(image_diff_pid), 60 zygote_diff_pid_(zygote_diff_pid) {} 61 62 bool Dump() SHARED_REQUIRES(Locks::mutator_lock_) { 63 std::ostream& os = *os_; 64 os << "IMAGE LOCATION: " << image_location_ << "\n\n"; 65 66 os << "MAGIC: " << image_header_.GetMagic() << "\n\n"; 67 68 os << "IMAGE BEGIN: " << reinterpret_cast<void*>(image_header_.GetImageBegin()) << "\n\n"; 69 70 bool ret = true; 71 if (image_diff_pid_ >= 0) { 72 os << "IMAGE DIFF PID (" << image_diff_pid_ << "): "; 73 ret = DumpImageDiff(image_diff_pid_, zygote_diff_pid_); 74 os << "\n\n"; 75 } else { 76 os << "IMAGE DIFF PID: disabled\n\n"; 77 } 78 79 os << std::flush; 80 81 return ret; 82 } 83 84 private: 85 static bool EndsWith(const std::string& str, const std::string& suffix) { 86 return str.size() >= suffix.size() && 87 str.compare(str.size() - suffix.size(), suffix.size(), suffix) == 0; 88 } 89 90 // Return suffix of the file path after the last /. (e.g. /foo/bar -> bar, bar -> bar) 91 static std::string BaseName(const std::string& str) { 92 size_t idx = str.rfind("/"); 93 if (idx == std::string::npos) { 94 return str; 95 } 96 97 return str.substr(idx + 1); 98 } 99 100 bool DumpImageDiff(pid_t image_diff_pid, pid_t zygote_diff_pid) 101 SHARED_REQUIRES(Locks::mutator_lock_) { 102 std::ostream& os = *os_; 103 104 { 105 struct stat sts; 106 std::string proc_pid_str = 107 StringPrintf("/proc/%ld", static_cast<long>(image_diff_pid)); // NOLINT [runtime/int] 108 if (stat(proc_pid_str.c_str(), &sts) == -1) { 109 os << "Process does not exist"; 110 return false; 111 } 112 } 113 114 // Open /proc/$pid/maps to view memory maps 115 auto proc_maps = std::unique_ptr<BacktraceMap>(BacktraceMap::Create(image_diff_pid)); 116 if (proc_maps == nullptr) { 117 os << "Could not read backtrace maps"; 118 return false; 119 } 120 121 bool found_boot_map = false; 122 backtrace_map_t boot_map = backtrace_map_t(); 123 // Find the memory map only for boot.art 124 for (const backtrace_map_t& map : *proc_maps) { 125 if (EndsWith(map.name, GetImageLocationBaseName())) { 126 if ((map.flags & PROT_WRITE) != 0) { 127 boot_map = map; 128 found_boot_map = true; 129 break; 130 } 131 // In actuality there's more than 1 map, but the second one is read-only. 132 // The one we care about is the write-able map. 133 // The readonly maps are guaranteed to be identical, so its not interesting to compare 134 // them. 135 } 136 } 137 138 if (!found_boot_map) { 139 os << "Could not find map for " << GetImageLocationBaseName(); 140 return false; 141 } 142 143 // Future idea: diff against zygote so we can ignore the shared dirty pages. 144 return DumpImageDiffMap(image_diff_pid, zygote_diff_pid, boot_map); 145 } 146 147 static std::string PrettyFieldValue(ArtField* field, mirror::Object* obj) 148 SHARED_REQUIRES(Locks::mutator_lock_) { 149 std::ostringstream oss; 150 switch (field->GetTypeAsPrimitiveType()) { 151 case Primitive::kPrimNot: { 152 oss << obj->GetFieldObject<mirror::Object, kVerifyNone, kWithoutReadBarrier>( 153 field->GetOffset()); 154 break; 155 } 156 case Primitive::kPrimBoolean: { 157 oss << static_cast<bool>(obj->GetFieldBoolean<kVerifyNone>(field->GetOffset())); 158 break; 159 } 160 case Primitive::kPrimByte: { 161 oss << static_cast<int32_t>(obj->GetFieldByte<kVerifyNone>(field->GetOffset())); 162 break; 163 } 164 case Primitive::kPrimChar: { 165 oss << obj->GetFieldChar<kVerifyNone>(field->GetOffset()); 166 break; 167 } 168 case Primitive::kPrimShort: { 169 oss << obj->GetFieldShort<kVerifyNone>(field->GetOffset()); 170 break; 171 } 172 case Primitive::kPrimInt: { 173 oss << obj->GetField32<kVerifyNone>(field->GetOffset()); 174 break; 175 } 176 case Primitive::kPrimLong: { 177 oss << obj->GetField64<kVerifyNone>(field->GetOffset()); 178 break; 179 } 180 case Primitive::kPrimFloat: { 181 oss << obj->GetField32<kVerifyNone>(field->GetOffset()); 182 break; 183 } 184 case Primitive::kPrimDouble: { 185 oss << obj->GetField64<kVerifyNone>(field->GetOffset()); 186 break; 187 } 188 case Primitive::kPrimVoid: { 189 oss << "void"; 190 break; 191 } 192 } 193 return oss.str(); 194 } 195 196 // Aggregate and detail class data from an image diff. 197 struct ClassData { 198 int dirty_object_count = 0; 199 200 // Track only the byte-per-byte dirtiness (in bytes) 201 int dirty_object_byte_count = 0; 202 203 // Track the object-by-object dirtiness (in bytes) 204 int dirty_object_size_in_bytes = 0; 205 206 int clean_object_count = 0; 207 208 std::string descriptor; 209 210 int false_dirty_byte_count = 0; 211 int false_dirty_object_count = 0; 212 std::vector<mirror::Object*> false_dirty_objects; 213 214 // Remote pointers to dirty objects 215 std::vector<mirror::Object*> dirty_objects; 216 }; 217 218 void DiffObjectContents(mirror::Object* obj, 219 uint8_t* remote_bytes, 220 std::ostream& os) SHARED_REQUIRES(Locks::mutator_lock_) { 221 const char* tabs = " "; 222 // Attempt to find fields for all dirty bytes. 223 mirror::Class* klass = obj->GetClass(); 224 if (obj->IsClass()) { 225 os << tabs << "Class " << PrettyClass(obj->AsClass()) << " " << obj << "\n"; 226 } else { 227 os << tabs << "Instance of " << PrettyClass(klass) << " " << obj << "\n"; 228 } 229 230 std::unordered_set<ArtField*> dirty_instance_fields; 231 std::unordered_set<ArtField*> dirty_static_fields; 232 const uint8_t* obj_bytes = reinterpret_cast<const uint8_t*>(obj); 233 mirror::Object* remote_obj = reinterpret_cast<mirror::Object*>(remote_bytes); 234 for (size_t i = 0, count = obj->SizeOf(); i < count; ++i) { 235 if (obj_bytes[i] != remote_bytes[i]) { 236 ArtField* field = ArtField::FindInstanceFieldWithOffset</*exact*/false>(klass, i); 237 if (field != nullptr) { 238 dirty_instance_fields.insert(field); 239 } else if (obj->IsClass()) { 240 field = ArtField::FindStaticFieldWithOffset</*exact*/false>(obj->AsClass(), i); 241 if (field != nullptr) { 242 dirty_static_fields.insert(field); 243 } 244 } 245 if (field == nullptr) { 246 if (klass->IsArrayClass()) { 247 mirror::Class* component_type = klass->GetComponentType(); 248 Primitive::Type primitive_type = component_type->GetPrimitiveType(); 249 size_t component_size = Primitive::ComponentSize(primitive_type); 250 size_t data_offset = mirror::Array::DataOffset(component_size).Uint32Value(); 251 if (i >= data_offset) { 252 os << tabs << "Dirty array element " << (i - data_offset) / component_size << "\n"; 253 // Skip to next element to prevent spam. 254 i += component_size - 1; 255 continue; 256 } 257 } 258 os << tabs << "No field for byte offset " << i << "\n"; 259 } 260 } 261 } 262 // Dump different fields. TODO: Dump field contents. 263 if (!dirty_instance_fields.empty()) { 264 os << tabs << "Dirty instance fields " << dirty_instance_fields.size() << "\n"; 265 for (ArtField* field : dirty_instance_fields) { 266 os << tabs << PrettyField(field) 267 << " original=" << PrettyFieldValue(field, obj) 268 << " remote=" << PrettyFieldValue(field, remote_obj) << "\n"; 269 } 270 } 271 if (!dirty_static_fields.empty()) { 272 os << tabs << "Dirty static fields " << dirty_static_fields.size() << "\n"; 273 for (ArtField* field : dirty_static_fields) { 274 os << tabs << PrettyField(field) 275 << " original=" << PrettyFieldValue(field, obj) 276 << " remote=" << PrettyFieldValue(field, remote_obj) << "\n"; 277 } 278 } 279 os << "\n"; 280 } 281 282 // Look at /proc/$pid/mem and only diff the things from there 283 bool DumpImageDiffMap(pid_t image_diff_pid, 284 pid_t zygote_diff_pid, 285 const backtrace_map_t& boot_map) 286 SHARED_REQUIRES(Locks::mutator_lock_) { 287 std::ostream& os = *os_; 288 const size_t pointer_size = InstructionSetPointerSize( 289 Runtime::Current()->GetInstructionSet()); 290 291 std::string file_name = 292 StringPrintf("/proc/%ld/mem", static_cast<long>(image_diff_pid)); // NOLINT [runtime/int] 293 294 size_t boot_map_size = boot_map.end - boot_map.start; 295 296 // Open /proc/$pid/mem as a file 297 auto map_file = std::unique_ptr<File>(OS::OpenFileForReading(file_name.c_str())); 298 if (map_file == nullptr) { 299 os << "Failed to open " << file_name << " for reading"; 300 return false; 301 } 302 303 // Memory-map /proc/$pid/mem subset from the boot map 304 CHECK(boot_map.end >= boot_map.start); 305 306 std::string error_msg; 307 308 // Walk the bytes and diff against our boot image 309 const ImageHeader& boot_image_header = image_header_; 310 311 os << "\nObserving boot image header at address " 312 << reinterpret_cast<const void*>(&boot_image_header) 313 << "\n\n"; 314 315 const uint8_t* image_begin_unaligned = boot_image_header.GetImageBegin(); 316 const uint8_t* image_mirror_end_unaligned = image_begin_unaligned + 317 boot_image_header.GetImageSection(ImageHeader::kSectionObjects).Size(); 318 const uint8_t* image_end_unaligned = image_begin_unaligned + boot_image_header.GetImageSize(); 319 320 // Adjust range to nearest page 321 const uint8_t* image_begin = AlignDown(image_begin_unaligned, kPageSize); 322 const uint8_t* image_end = AlignUp(image_end_unaligned, kPageSize); 323 324 ptrdiff_t page_off_begin = boot_image_header.GetImageBegin() - image_begin; 325 326 if (reinterpret_cast<uintptr_t>(image_begin) > boot_map.start || 327 reinterpret_cast<uintptr_t>(image_end) < boot_map.end) { 328 // Sanity check that we aren't trying to read a completely different boot image 329 os << "Remote boot map is out of range of local boot map: " << 330 "local begin " << reinterpret_cast<const void*>(image_begin) << 331 ", local end " << reinterpret_cast<const void*>(image_end) << 332 ", remote begin " << reinterpret_cast<const void*>(boot_map.start) << 333 ", remote end " << reinterpret_cast<const void*>(boot_map.end); 334 return false; 335 // If we wanted even more validation we could map the ImageHeader from the file 336 } 337 338 std::vector<uint8_t> remote_contents(boot_map_size); 339 if (!map_file->PreadFully(&remote_contents[0], boot_map_size, boot_map.start)) { 340 os << "Could not fully read file " << file_name; 341 return false; 342 } 343 344 std::vector<uint8_t> zygote_contents; 345 std::unique_ptr<File> zygote_map_file; 346 if (zygote_diff_pid != -1) { 347 std::string zygote_file_name = 348 StringPrintf("/proc/%ld/mem", static_cast<long>(zygote_diff_pid)); // NOLINT [runtime/int] 349 zygote_map_file.reset(OS::OpenFileForReading(zygote_file_name.c_str())); 350 // The boot map should be at the same address. 351 zygote_contents.resize(boot_map_size); 352 if (!zygote_map_file->PreadFully(&zygote_contents[0], boot_map_size, boot_map.start)) { 353 LOG(WARNING) << "Could not fully read zygote file " << zygote_file_name; 354 zygote_contents.clear(); 355 } 356 } 357 358 std::string page_map_file_name = StringPrintf( 359 "/proc/%ld/pagemap", static_cast<long>(image_diff_pid)); // NOLINT [runtime/int] 360 auto page_map_file = std::unique_ptr<File>(OS::OpenFileForReading(page_map_file_name.c_str())); 361 if (page_map_file == nullptr) { 362 os << "Failed to open " << page_map_file_name << " for reading: " << strerror(errno); 363 return false; 364 } 365 366 // Not truly clean, mmap-ing boot.art again would be more pristine, but close enough 367 const char* clean_page_map_file_name = "/proc/self/pagemap"; 368 auto clean_page_map_file = std::unique_ptr<File>( 369 OS::OpenFileForReading(clean_page_map_file_name)); 370 if (clean_page_map_file == nullptr) { 371 os << "Failed to open " << clean_page_map_file_name << " for reading: " << strerror(errno); 372 return false; 373 } 374 375 auto kpage_flags_file = std::unique_ptr<File>(OS::OpenFileForReading("/proc/kpageflags")); 376 if (kpage_flags_file == nullptr) { 377 os << "Failed to open /proc/kpageflags for reading: " << strerror(errno); 378 return false; 379 } 380 381 auto kpage_count_file = std::unique_ptr<File>(OS::OpenFileForReading("/proc/kpagecount")); 382 if (kpage_count_file == nullptr) { 383 os << "Failed to open /proc/kpagecount for reading:" << strerror(errno); 384 return false; 385 } 386 387 // Set of the remote virtual page indices that are dirty 388 std::set<size_t> dirty_page_set_remote; 389 // Set of the local virtual page indices that are dirty 390 std::set<size_t> dirty_page_set_local; 391 392 size_t different_int32s = 0; 393 size_t different_bytes = 0; 394 size_t different_pages = 0; 395 size_t virtual_page_idx = 0; // Virtual page number (for an absolute memory address) 396 size_t page_idx = 0; // Page index relative to 0 397 size_t previous_page_idx = 0; // Previous page index relative to 0 398 size_t dirty_pages = 0; 399 size_t private_pages = 0; 400 size_t private_dirty_pages = 0; 401 402 // Iterate through one page at a time. Boot map begin/end already implicitly aligned. 403 for (uintptr_t begin = boot_map.start; begin != boot_map.end; begin += kPageSize) { 404 ptrdiff_t offset = begin - boot_map.start; 405 406 // We treat the image header as part of the memory map for now 407 // If we wanted to change this, we could pass base=start+sizeof(ImageHeader) 408 // But it might still be interesting to see if any of the ImageHeader data mutated 409 const uint8_t* local_ptr = reinterpret_cast<const uint8_t*>(&boot_image_header) + offset; 410 uint8_t* remote_ptr = &remote_contents[offset]; 411 412 if (memcmp(local_ptr, remote_ptr, kPageSize) != 0) { 413 different_pages++; 414 415 // Count the number of 32-bit integers that are different. 416 for (size_t i = 0; i < kPageSize / sizeof(uint32_t); ++i) { 417 uint32_t* remote_ptr_int32 = reinterpret_cast<uint32_t*>(remote_ptr); 418 const uint32_t* local_ptr_int32 = reinterpret_cast<const uint32_t*>(local_ptr); 419 420 if (remote_ptr_int32[i] != local_ptr_int32[i]) { 421 different_int32s++; 422 } 423 } 424 } 425 } 426 427 // Iterate through one byte at a time. 428 for (uintptr_t begin = boot_map.start; begin != boot_map.end; ++begin) { 429 previous_page_idx = page_idx; 430 ptrdiff_t offset = begin - boot_map.start; 431 432 // We treat the image header as part of the memory map for now 433 // If we wanted to change this, we could pass base=start+sizeof(ImageHeader) 434 // But it might still be interesting to see if any of the ImageHeader data mutated 435 const uint8_t* local_ptr = reinterpret_cast<const uint8_t*>(&boot_image_header) + offset; 436 uint8_t* remote_ptr = &remote_contents[offset]; 437 438 virtual_page_idx = reinterpret_cast<uintptr_t>(local_ptr) / kPageSize; 439 440 // Calculate the page index, relative to the 0th page where the image begins 441 page_idx = (offset + page_off_begin) / kPageSize; 442 if (*local_ptr != *remote_ptr) { 443 // Track number of bytes that are different 444 different_bytes++; 445 } 446 447 // Independently count the # of dirty pages on the remote side 448 size_t remote_virtual_page_idx = begin / kPageSize; 449 if (previous_page_idx != page_idx) { 450 uint64_t page_count = 0xC0FFEE; 451 // TODO: virtual_page_idx needs to be from the same process 452 int dirtiness = (IsPageDirty(page_map_file.get(), // Image-diff-pid procmap 453 clean_page_map_file.get(), // Self procmap 454 kpage_flags_file.get(), 455 kpage_count_file.get(), 456 remote_virtual_page_idx, // potentially "dirty" page 457 virtual_page_idx, // true "clean" page 458 &page_count, 459 &error_msg)); 460 if (dirtiness < 0) { 461 os << error_msg; 462 return false; 463 } else if (dirtiness > 0) { 464 dirty_pages++; 465 dirty_page_set_remote.insert(dirty_page_set_remote.end(), remote_virtual_page_idx); 466 dirty_page_set_local.insert(dirty_page_set_local.end(), virtual_page_idx); 467 } 468 469 bool is_dirty = dirtiness > 0; 470 bool is_private = page_count == 1; 471 472 if (page_count == 1) { 473 private_pages++; 474 } 475 476 if (is_dirty && is_private) { 477 private_dirty_pages++; 478 } 479 } 480 } 481 482 std::map<mirror::Class*, ClassData> class_data; 483 484 // Walk each object in the remote image space and compare it against ours 485 size_t different_objects = 0; 486 487 std::map<off_t /* field offset */, int /* count */> art_method_field_dirty_count; 488 std::vector<ArtMethod*> art_method_dirty_objects; 489 490 std::map<off_t /* field offset */, int /* count */> class_field_dirty_count; 491 std::vector<mirror::Class*> class_dirty_objects; 492 493 // List of local objects that are clean, but located on dirty pages. 494 std::vector<mirror::Object*> false_dirty_objects; 495 size_t false_dirty_object_bytes = 0; 496 497 // Look up remote classes by their descriptor 498 std::map<std::string, mirror::Class*> remote_class_map; 499 // Look up local classes by their descriptor 500 std::map<std::string, mirror::Class*> local_class_map; 501 502 // Objects that are dirty against the image (possibly shared or private dirty). 503 std::set<mirror::Object*> image_dirty_objects; 504 505 // Objects that are dirty against the zygote (probably private dirty). 506 std::set<mirror::Object*> zygote_dirty_objects; 507 508 size_t dirty_object_bytes = 0; 509 const uint8_t* begin_image_ptr = image_begin_unaligned; 510 const uint8_t* end_image_ptr = image_mirror_end_unaligned; 511 512 const uint8_t* current = begin_image_ptr + RoundUp(sizeof(ImageHeader), kObjectAlignment); 513 while (reinterpret_cast<uintptr_t>(current) < reinterpret_cast<uintptr_t>(end_image_ptr)) { 514 CHECK_ALIGNED(current, kObjectAlignment); 515 mirror::Object* obj = reinterpret_cast<mirror::Object*>(const_cast<uint8_t*>(current)); 516 517 // Sanity check that we are reading a real object 518 CHECK(obj->GetClass() != nullptr) << "Image object at address " << obj << " has null class"; 519 if (kUseBakerOrBrooksReadBarrier) { 520 obj->AssertReadBarrierPointer(); 521 } 522 523 // Iterate every page this object belongs to 524 bool on_dirty_page = false; 525 size_t page_off = 0; 526 size_t current_page_idx; 527 uintptr_t object_address; 528 do { 529 object_address = reinterpret_cast<uintptr_t>(current); 530 current_page_idx = object_address / kPageSize + page_off; 531 532 if (dirty_page_set_local.find(current_page_idx) != dirty_page_set_local.end()) { 533 // This object is on a dirty page 534 on_dirty_page = true; 535 } 536 537 page_off++; 538 } while ((current_page_idx * kPageSize) < 539 RoundUp(object_address + obj->SizeOf(), kObjectAlignment)); 540 541 mirror::Class* klass = obj->GetClass(); 542 543 // Check against the other object and see if they are different 544 ptrdiff_t offset = current - begin_image_ptr; 545 const uint8_t* current_remote = &remote_contents[offset]; 546 mirror::Object* remote_obj = reinterpret_cast<mirror::Object*>( 547 const_cast<uint8_t*>(current_remote)); 548 549 bool different_image_object = memcmp(current, current_remote, obj->SizeOf()) != 0; 550 if (different_image_object) { 551 bool different_zygote_object = false; 552 if (!zygote_contents.empty()) { 553 const uint8_t* zygote_ptr = &zygote_contents[offset]; 554 different_zygote_object = memcmp(current, zygote_ptr, obj->SizeOf()) != 0; 555 } 556 if (different_zygote_object) { 557 // Different from zygote. 558 zygote_dirty_objects.insert(obj); 559 } else { 560 // Just different from iamge. 561 image_dirty_objects.insert(obj); 562 } 563 564 different_objects++; 565 dirty_object_bytes += obj->SizeOf(); 566 567 ++class_data[klass].dirty_object_count; 568 569 // Go byte-by-byte and figure out what exactly got dirtied 570 size_t dirty_byte_count_per_object = 0; 571 for (size_t i = 0; i < obj->SizeOf(); ++i) { 572 if (current[i] != current_remote[i]) { 573 dirty_byte_count_per_object++; 574 } 575 } 576 class_data[klass].dirty_object_byte_count += dirty_byte_count_per_object; 577 class_data[klass].dirty_object_size_in_bytes += obj->SizeOf(); 578 class_data[klass].dirty_objects.push_back(remote_obj); 579 } else { 580 ++class_data[klass].clean_object_count; 581 } 582 583 std::string descriptor = GetClassDescriptor(klass); 584 if (different_image_object) { 585 if (klass->IsClassClass()) { 586 // this is a "Class" 587 mirror::Class* obj_as_class = reinterpret_cast<mirror::Class*>(remote_obj); 588 589 // print the fields that are dirty 590 for (size_t i = 0; i < obj->SizeOf(); ++i) { 591 if (current[i] != current_remote[i]) { 592 class_field_dirty_count[i]++; 593 } 594 } 595 596 class_dirty_objects.push_back(obj_as_class); 597 } else if (strcmp(descriptor.c_str(), "Ljava/lang/reflect/ArtMethod;") == 0) { 598 // this is an ArtMethod 599 ArtMethod* art_method = reinterpret_cast<ArtMethod*>(remote_obj); 600 601 // print the fields that are dirty 602 for (size_t i = 0; i < obj->SizeOf(); ++i) { 603 if (current[i] != current_remote[i]) { 604 art_method_field_dirty_count[i]++; 605 } 606 } 607 608 art_method_dirty_objects.push_back(art_method); 609 } 610 } else if (on_dirty_page) { 611 // This object was either never mutated or got mutated back to the same value. 612 // TODO: Do I want to distinguish a "different" vs a "dirty" page here? 613 false_dirty_objects.push_back(obj); 614 class_data[klass].false_dirty_objects.push_back(obj); 615 false_dirty_object_bytes += obj->SizeOf(); 616 class_data[obj->GetClass()].false_dirty_byte_count += obj->SizeOf(); 617 class_data[obj->GetClass()].false_dirty_object_count += 1; 618 } 619 620 if (strcmp(descriptor.c_str(), "Ljava/lang/Class;") == 0) { 621 local_class_map[descriptor] = reinterpret_cast<mirror::Class*>(obj); 622 remote_class_map[descriptor] = reinterpret_cast<mirror::Class*>(remote_obj); 623 } 624 625 // Unconditionally store the class descriptor in case we need it later 626 class_data[klass].descriptor = descriptor; 627 current += RoundUp(obj->SizeOf(), kObjectAlignment); 628 } 629 630 // Looking at only dirty pages, figure out how many of those bytes belong to dirty objects. 631 float true_dirtied_percent = dirty_object_bytes * 1.0f / (dirty_pages * kPageSize); 632 size_t false_dirty_pages = dirty_pages - different_pages; 633 634 os << "Mapping at [" << reinterpret_cast<void*>(boot_map.start) << ", " 635 << reinterpret_cast<void*>(boot_map.end) << ") had: \n " 636 << different_bytes << " differing bytes, \n " 637 << different_int32s << " differing int32s, \n " 638 << different_objects << " different objects, \n " 639 << dirty_object_bytes << " different object [bytes], \n " 640 << false_dirty_objects.size() << " false dirty objects,\n " 641 << false_dirty_object_bytes << " false dirty object [bytes], \n " 642 << true_dirtied_percent << " different objects-vs-total in a dirty page;\n " 643 << different_pages << " different pages; \n " 644 << dirty_pages << " pages are dirty; \n " 645 << false_dirty_pages << " pages are false dirty; \n " 646 << private_pages << " pages are private; \n " 647 << private_dirty_pages << " pages are Private_Dirty\n " 648 << ""; 649 650 // vector of pairs (int count, Class*) 651 auto dirty_object_class_values = SortByValueDesc<mirror::Class*, int, ClassData>( 652 class_data, [](const ClassData& d) { return d.dirty_object_count; }); 653 auto clean_object_class_values = SortByValueDesc<mirror::Class*, int, ClassData>( 654 class_data, [](const ClassData& d) { return d.clean_object_count; }); 655 656 if (!zygote_dirty_objects.empty()) { 657 os << "\n" << " Dirty objects compared to zygote (probably private dirty): " 658 << zygote_dirty_objects.size() << "\n"; 659 for (mirror::Object* obj : zygote_dirty_objects) { 660 const uint8_t* obj_bytes = reinterpret_cast<const uint8_t*>(obj); 661 ptrdiff_t offset = obj_bytes - begin_image_ptr; 662 uint8_t* remote_bytes = &zygote_contents[offset]; 663 DiffObjectContents(obj, remote_bytes, os); 664 } 665 } 666 os << "\n" << " Dirty objects compared to image (private or shared dirty): " 667 << image_dirty_objects.size() << "\n"; 668 for (mirror::Object* obj : image_dirty_objects) { 669 const uint8_t* obj_bytes = reinterpret_cast<const uint8_t*>(obj); 670 ptrdiff_t offset = obj_bytes - begin_image_ptr; 671 uint8_t* remote_bytes = &remote_contents[offset]; 672 DiffObjectContents(obj, remote_bytes, os); 673 } 674 675 os << "\n" << " Dirty object count by class:\n"; 676 for (const auto& vk_pair : dirty_object_class_values) { 677 int dirty_object_count = vk_pair.first; 678 mirror::Class* klass = vk_pair.second; 679 int object_sizes = class_data[klass].dirty_object_size_in_bytes; 680 float avg_dirty_bytes_per_class = 681 class_data[klass].dirty_object_byte_count * 1.0f / object_sizes; 682 float avg_object_size = object_sizes * 1.0f / dirty_object_count; 683 const std::string& descriptor = class_data[klass].descriptor; 684 os << " " << PrettyClass(klass) << " (" 685 << "objects: " << dirty_object_count << ", " 686 << "avg dirty bytes: " << avg_dirty_bytes_per_class << ", " 687 << "avg object size: " << avg_object_size << ", " 688 << "class descriptor: '" << descriptor << "'" 689 << ")\n"; 690 691 constexpr size_t kMaxAddressPrint = 5; 692 if (strcmp(descriptor.c_str(), "Ljava/lang/reflect/ArtMethod;") == 0) { 693 os << " sample object addresses: "; 694 for (size_t i = 0; i < art_method_dirty_objects.size() && i < kMaxAddressPrint; ++i) { 695 auto art_method = art_method_dirty_objects[i]; 696 697 os << reinterpret_cast<void*>(art_method) << ", "; 698 } 699 os << "\n"; 700 701 os << " dirty byte +offset:count list = "; 702 auto art_method_field_dirty_count_sorted = 703 SortByValueDesc<off_t, int, int>(art_method_field_dirty_count); 704 for (auto pair : art_method_field_dirty_count_sorted) { 705 off_t offset = pair.second; 706 int count = pair.first; 707 708 os << "+" << offset << ":" << count << ", "; 709 } 710 711 os << "\n"; 712 713 os << " field contents:\n"; 714 const auto& dirty_objects_list = class_data[klass].dirty_objects; 715 for (mirror::Object* obj : dirty_objects_list) { 716 // remote method 717 auto art_method = reinterpret_cast<ArtMethod*>(obj); 718 719 // remote class 720 mirror::Class* remote_declaring_class = 721 FixUpRemotePointer(art_method->GetDeclaringClass(), remote_contents, boot_map); 722 723 // local class 724 mirror::Class* declaring_class = 725 RemoteContentsPointerToLocal(remote_declaring_class, 726 remote_contents, 727 boot_image_header); 728 729 os << " " << reinterpret_cast<void*>(obj) << " "; 730 os << " entryPointFromJni: " 731 << reinterpret_cast<const void*>( 732 art_method->GetEntryPointFromJniPtrSize(pointer_size)) << ", "; 733 os << " entryPointFromQuickCompiledCode: " 734 << reinterpret_cast<const void*>( 735 art_method->GetEntryPointFromQuickCompiledCodePtrSize(pointer_size)) 736 << ", "; 737 os << " isNative? " << (art_method->IsNative() ? "yes" : "no") << ", "; 738 os << " class_status (local): " << declaring_class->GetStatus(); 739 os << " class_status (remote): " << remote_declaring_class->GetStatus(); 740 os << "\n"; 741 } 742 } 743 if (strcmp(descriptor.c_str(), "Ljava/lang/Class;") == 0) { 744 os << " sample object addresses: "; 745 for (size_t i = 0; i < class_dirty_objects.size() && i < kMaxAddressPrint; ++i) { 746 auto class_ptr = class_dirty_objects[i]; 747 748 os << reinterpret_cast<void*>(class_ptr) << ", "; 749 } 750 os << "\n"; 751 752 os << " dirty byte +offset:count list = "; 753 auto class_field_dirty_count_sorted = 754 SortByValueDesc<off_t, int, int>(class_field_dirty_count); 755 for (auto pair : class_field_dirty_count_sorted) { 756 off_t offset = pair.second; 757 int count = pair.first; 758 759 os << "+" << offset << ":" << count << ", "; 760 } 761 os << "\n"; 762 763 os << " field contents:\n"; 764 const auto& dirty_objects_list = class_data[klass].dirty_objects; 765 for (mirror::Object* obj : dirty_objects_list) { 766 // remote class object 767 auto remote_klass = reinterpret_cast<mirror::Class*>(obj); 768 769 // local class object 770 auto local_klass = RemoteContentsPointerToLocal(remote_klass, 771 remote_contents, 772 boot_image_header); 773 774 os << " " << reinterpret_cast<void*>(obj) << " "; 775 os << " class_status (remote): " << remote_klass->GetStatus() << ", "; 776 os << " class_status (local): " << local_klass->GetStatus(); 777 os << "\n"; 778 } 779 } 780 } 781 782 auto false_dirty_object_class_values = SortByValueDesc<mirror::Class*, int, ClassData>( 783 class_data, [](const ClassData& d) { return d.false_dirty_object_count; }); 784 785 os << "\n" << " False-dirty object count by class:\n"; 786 for (const auto& vk_pair : false_dirty_object_class_values) { 787 int object_count = vk_pair.first; 788 mirror::Class* klass = vk_pair.second; 789 int object_sizes = class_data[klass].false_dirty_byte_count; 790 float avg_object_size = object_sizes * 1.0f / object_count; 791 const std::string& descriptor = class_data[klass].descriptor; 792 os << " " << PrettyClass(klass) << " (" 793 << "objects: " << object_count << ", " 794 << "avg object size: " << avg_object_size << ", " 795 << "total bytes: " << object_sizes << ", " 796 << "class descriptor: '" << descriptor << "'" 797 << ")\n"; 798 799 if (strcmp(descriptor.c_str(), "Ljava/lang/reflect/ArtMethod;") == 0) { 800 auto& art_method_false_dirty_objects = class_data[klass].false_dirty_objects; 801 802 os << " field contents:\n"; 803 for (mirror::Object* obj : art_method_false_dirty_objects) { 804 // local method 805 auto art_method = reinterpret_cast<ArtMethod*>(obj); 806 807 // local class 808 mirror::Class* declaring_class = art_method->GetDeclaringClass(); 809 810 os << " " << reinterpret_cast<void*>(obj) << " "; 811 os << " entryPointFromJni: " 812 << reinterpret_cast<const void*>( 813 art_method->GetEntryPointFromJniPtrSize(pointer_size)) << ", "; 814 os << " entryPointFromQuickCompiledCode: " 815 << reinterpret_cast<const void*>( 816 art_method->GetEntryPointFromQuickCompiledCodePtrSize(pointer_size)) 817 << ", "; 818 os << " isNative? " << (art_method->IsNative() ? "yes" : "no") << ", "; 819 os << " class_status (local): " << declaring_class->GetStatus(); 820 os << "\n"; 821 } 822 } 823 } 824 825 os << "\n" << " Clean object count by class:\n"; 826 for (const auto& vk_pair : clean_object_class_values) { 827 os << " " << PrettyClass(vk_pair.second) << " (" << vk_pair.first << ")\n"; 828 } 829 830 return true; 831 } 832 833 // Fixup a remote pointer that we read from a foreign boot.art to point to our own memory. 834 // Returned pointer will point to inside of remote_contents. 835 template <typename T> 836 static T* FixUpRemotePointer(T* remote_ptr, 837 std::vector<uint8_t>& remote_contents, 838 const backtrace_map_t& boot_map) { 839 if (remote_ptr == nullptr) { 840 return nullptr; 841 } 842 843 uintptr_t remote = reinterpret_cast<uintptr_t>(remote_ptr); 844 845 CHECK_LE(boot_map.start, remote); 846 CHECK_GT(boot_map.end, remote); 847 848 off_t boot_offset = remote - boot_map.start; 849 850 return reinterpret_cast<T*>(&remote_contents[boot_offset]); 851 } 852 853 template <typename T> 854 static T* RemoteContentsPointerToLocal(T* remote_ptr, 855 std::vector<uint8_t>& remote_contents, 856 const ImageHeader& image_header) { 857 if (remote_ptr == nullptr) { 858 return nullptr; 859 } 860 861 uint8_t* remote = reinterpret_cast<uint8_t*>(remote_ptr); 862 ptrdiff_t boot_offset = remote - &remote_contents[0]; 863 864 const uint8_t* local_ptr = reinterpret_cast<const uint8_t*>(&image_header) + boot_offset; 865 866 return reinterpret_cast<T*>(const_cast<uint8_t*>(local_ptr)); 867 } 868 869 static std::string GetClassDescriptor(mirror::Class* klass) 870 SHARED_REQUIRES(Locks::mutator_lock_) { 871 CHECK(klass != nullptr); 872 873 std::string descriptor; 874 const char* descriptor_str = klass->GetDescriptor(&descriptor); 875 876 return std::string(descriptor_str); 877 } 878 879 template <typename K, typename V, typename D> 880 static std::vector<std::pair<V, K>> SortByValueDesc( 881 const std::map<K, D> map, 882 std::function<V(const D&)> value_mapper = [](const D& d) { return static_cast<V>(d); }) { 883 // Store value->key so that we can use the default sort from pair which 884 // sorts by value first and then key 885 std::vector<std::pair<V, K>> value_key_vector; 886 887 for (const auto& kv_pair : map) { 888 value_key_vector.push_back(std::make_pair(value_mapper(kv_pair.second), kv_pair.first)); 889 } 890 891 // Sort in reverse (descending order) 892 std::sort(value_key_vector.rbegin(), value_key_vector.rend()); 893 return value_key_vector; 894 } 895 896 static bool GetPageFrameNumber(File* page_map_file, 897 size_t virtual_page_index, 898 uint64_t* page_frame_number, 899 std::string* error_msg) { 900 CHECK(page_map_file != nullptr); 901 CHECK(page_frame_number != nullptr); 902 CHECK(error_msg != nullptr); 903 904 constexpr size_t kPageMapEntrySize = sizeof(uint64_t); 905 constexpr uint64_t kPageFrameNumberMask = (1ULL << 55) - 1; // bits 0-54 [in /proc/$pid/pagemap] 906 constexpr uint64_t kPageSoftDirtyMask = (1ULL << 55); // bit 55 [in /proc/$pid/pagemap] 907 908 uint64_t page_map_entry = 0; 909 910 // Read 64-bit entry from /proc/$pid/pagemap to get the physical page frame number 911 if (!page_map_file->PreadFully(&page_map_entry, kPageMapEntrySize, 912 virtual_page_index * kPageMapEntrySize)) { 913 *error_msg = StringPrintf("Failed to read the virtual page index entry from %s", 914 page_map_file->GetPath().c_str()); 915 return false; 916 } 917 918 // TODO: seems useless, remove this. 919 bool soft_dirty = (page_map_entry & kPageSoftDirtyMask) != 0; 920 if ((false)) { 921 LOG(VERBOSE) << soft_dirty; // Suppress unused warning 922 UNREACHABLE(); 923 } 924 925 *page_frame_number = page_map_entry & kPageFrameNumberMask; 926 927 return true; 928 } 929 930 static int IsPageDirty(File* page_map_file, 931 File* clean_page_map_file, 932 File* kpage_flags_file, 933 File* kpage_count_file, 934 size_t virtual_page_idx, 935 size_t clean_virtual_page_idx, 936 // Out parameters: 937 uint64_t* page_count, std::string* error_msg) { 938 CHECK(page_map_file != nullptr); 939 CHECK(clean_page_map_file != nullptr); 940 CHECK_NE(page_map_file, clean_page_map_file); 941 CHECK(kpage_flags_file != nullptr); 942 CHECK(kpage_count_file != nullptr); 943 CHECK(page_count != nullptr); 944 CHECK(error_msg != nullptr); 945 946 // Constants are from https://www.kernel.org/doc/Documentation/vm/pagemap.txt 947 948 constexpr size_t kPageFlagsEntrySize = sizeof(uint64_t); 949 constexpr size_t kPageCountEntrySize = sizeof(uint64_t); 950 constexpr uint64_t kPageFlagsDirtyMask = (1ULL << 4); // in /proc/kpageflags 951 constexpr uint64_t kPageFlagsNoPageMask = (1ULL << 20); // in /proc/kpageflags 952 constexpr uint64_t kPageFlagsMmapMask = (1ULL << 11); // in /proc/kpageflags 953 954 uint64_t page_frame_number = 0; 955 if (!GetPageFrameNumber(page_map_file, virtual_page_idx, &page_frame_number, error_msg)) { 956 return -1; 957 } 958 959 uint64_t page_frame_number_clean = 0; 960 if (!GetPageFrameNumber(clean_page_map_file, clean_virtual_page_idx, &page_frame_number_clean, 961 error_msg)) { 962 return -1; 963 } 964 965 // Read 64-bit entry from /proc/kpageflags to get the dirty bit for a page 966 uint64_t kpage_flags_entry = 0; 967 if (!kpage_flags_file->PreadFully(&kpage_flags_entry, 968 kPageFlagsEntrySize, 969 page_frame_number * kPageFlagsEntrySize)) { 970 *error_msg = StringPrintf("Failed to read the page flags from %s", 971 kpage_flags_file->GetPath().c_str()); 972 return -1; 973 } 974 975 // Read 64-bit entyry from /proc/kpagecount to get mapping counts for a page 976 if (!kpage_count_file->PreadFully(page_count /*out*/, 977 kPageCountEntrySize, 978 page_frame_number * kPageCountEntrySize)) { 979 *error_msg = StringPrintf("Failed to read the page count from %s", 980 kpage_count_file->GetPath().c_str()); 981 return -1; 982 } 983 984 // There must be a page frame at the requested address. 985 CHECK_EQ(kpage_flags_entry & kPageFlagsNoPageMask, 0u); 986 // The page frame must be memory mapped 987 CHECK_NE(kpage_flags_entry & kPageFlagsMmapMask, 0u); 988 989 // Page is dirty, i.e. has diverged from file, if the 4th bit is set to 1 990 bool flags_dirty = (kpage_flags_entry & kPageFlagsDirtyMask) != 0; 991 992 // page_frame_number_clean must come from the *same* process 993 // but a *different* mmap than page_frame_number 994 if (flags_dirty) { 995 CHECK_NE(page_frame_number, page_frame_number_clean); 996 } 997 998 return page_frame_number != page_frame_number_clean; 999 } 1000 1001 private: 1002 // Return the image location, stripped of any directories, e.g. "boot.art" or "core.art" 1003 std::string GetImageLocationBaseName() const { 1004 return BaseName(std::string(image_location_)); 1005 } 1006 1007 std::ostream* os_; 1008 const ImageHeader& image_header_; 1009 const std::string image_location_; 1010 pid_t image_diff_pid_; // Dump image diff against boot.art if pid is non-negative 1011 pid_t zygote_diff_pid_; // Dump image diff against zygote boot.art if pid is non-negative 1012 1013 DISALLOW_COPY_AND_ASSIGN(ImgDiagDumper); 1014 }; 1015 1016 static int DumpImage(Runtime* runtime, 1017 std::ostream* os, 1018 pid_t image_diff_pid, 1019 pid_t zygote_diff_pid) { 1020 ScopedObjectAccess soa(Thread::Current()); 1021 gc::Heap* heap = runtime->GetHeap(); 1022 std::vector<gc::space::ImageSpace*> image_spaces = heap->GetBootImageSpaces(); 1023 CHECK(!image_spaces.empty()); 1024 for (gc::space::ImageSpace* image_space : image_spaces) { 1025 const ImageHeader& image_header = image_space->GetImageHeader(); 1026 if (!image_header.IsValid()) { 1027 fprintf(stderr, "Invalid image header %s\n", image_space->GetImageLocation().c_str()); 1028 return EXIT_FAILURE; 1029 } 1030 1031 ImgDiagDumper img_diag_dumper(os, 1032 image_header, 1033 image_space->GetImageLocation(), 1034 image_diff_pid, 1035 zygote_diff_pid); 1036 if (!img_diag_dumper.Dump()) { 1037 return EXIT_FAILURE; 1038 } 1039 } 1040 return EXIT_SUCCESS; 1041 } 1042 1043 struct ImgDiagArgs : public CmdlineArgs { 1044 protected: 1045 using Base = CmdlineArgs; 1046 1047 virtual ParseStatus ParseCustom(const StringPiece& option, 1048 std::string* error_msg) OVERRIDE { 1049 { 1050 ParseStatus base_parse = Base::ParseCustom(option, error_msg); 1051 if (base_parse != kParseUnknownArgument) { 1052 return base_parse; 1053 } 1054 } 1055 1056 if (option.starts_with("--image-diff-pid=")) { 1057 const char* image_diff_pid = option.substr(strlen("--image-diff-pid=")).data(); 1058 1059 if (!ParseInt(image_diff_pid, &image_diff_pid_)) { 1060 *error_msg = "Image diff pid out of range"; 1061 return kParseError; 1062 } 1063 } else if (option.starts_with("--zygote-diff-pid=")) { 1064 const char* zygote_diff_pid = option.substr(strlen("--zygote-diff-pid=")).data(); 1065 1066 if (!ParseInt(zygote_diff_pid, &zygote_diff_pid_)) { 1067 *error_msg = "Zygote diff pid out of range"; 1068 return kParseError; 1069 } 1070 } else { 1071 return kParseUnknownArgument; 1072 } 1073 1074 return kParseOk; 1075 } 1076 1077 virtual ParseStatus ParseChecks(std::string* error_msg) OVERRIDE { 1078 // Perform the parent checks. 1079 ParseStatus parent_checks = Base::ParseChecks(error_msg); 1080 if (parent_checks != kParseOk) { 1081 return parent_checks; 1082 } 1083 1084 // Perform our own checks. 1085 1086 if (kill(image_diff_pid_, 1087 /*sig*/0) != 0) { // No signal is sent, perform error-checking only. 1088 // Check if the pid exists before proceeding. 1089 if (errno == ESRCH) { 1090 *error_msg = "Process specified does not exist"; 1091 } else { 1092 *error_msg = StringPrintf("Failed to check process status: %s", strerror(errno)); 1093 } 1094 return kParseError; 1095 } else if (instruction_set_ != kRuntimeISA) { 1096 // Don't allow different ISAs since the images are ISA-specific. 1097 // Right now the code assumes both the runtime ISA and the remote ISA are identical. 1098 *error_msg = "Must use the default runtime ISA; changing ISA is not supported."; 1099 return kParseError; 1100 } 1101 1102 return kParseOk; 1103 } 1104 1105 virtual std::string GetUsage() const { 1106 std::string usage; 1107 1108 usage += 1109 "Usage: imgdiag [options] ...\n" 1110 " Example: imgdiag --image-diff-pid=$(pidof dex2oat)\n" 1111 " Example: adb shell imgdiag --image-diff-pid=$(pid zygote)\n" 1112 "\n"; 1113 1114 usage += Base::GetUsage(); 1115 1116 usage += // Optional. 1117 " --image-diff-pid=<pid>: provide the PID of a process whose boot.art you want to diff.\n" 1118 " Example: --image-diff-pid=$(pid zygote)\n" 1119 " --zygote-diff-pid=<pid>: provide the PID of the zygote whose boot.art you want to diff " 1120 "against.\n" 1121 " Example: --zygote-diff-pid=$(pid zygote)\n" 1122 "\n"; 1123 1124 return usage; 1125 } 1126 1127 public: 1128 pid_t image_diff_pid_ = -1; 1129 pid_t zygote_diff_pid_ = -1; 1130 }; 1131 1132 struct ImgDiagMain : public CmdlineMain<ImgDiagArgs> { 1133 virtual bool ExecuteWithRuntime(Runtime* runtime) { 1134 CHECK(args_ != nullptr); 1135 1136 return DumpImage(runtime, 1137 args_->os_, 1138 args_->image_diff_pid_, 1139 args_->zygote_diff_pid_) == EXIT_SUCCESS; 1140 } 1141 }; 1142 1143 } // namespace art 1144 1145 int main(int argc, char** argv) { 1146 art::ImgDiagMain main; 1147 return main.Main(argc, argv); 1148 } 1149
